The subject invention relates to a voltage regulator receiving an input voltage and generating a regulated output voltage; the subject invention also relates to a low dropout voltage regulator or an LDO where the input source of voltage is substantially fixed and the regulator output voltage is maintained at a substantially constant level.
Low dropout voltage regulators or LDOs, sometimes referred to as DC linear voltage regulators, are used to convert an input supply voltage from the input voltage VIN to a desired output voltage VOUT on an output node. The output voltage can be maintained to have a substantially constant magnitude.
Feedback control circuits are used to regulate and control the power. In some applications, the output voltage can be adjusted externally to a desirable level through at least one resistor coupled to the feedback signal which is generated from the regulator output voltage.
In modern low dropout voltage regulator or LDO design, one of the challenging tasks is to support high load current over a wide range of operating conditions. In order to improve an LDO voltage regulator, various techniques have been used in the prior arts.